Our political systems in the free world are very resistant to change. A party can be founded to further an important topic but people demand that they have a broader program and address all kinds of topics.
And then you end up with another copy of some party.
Then, you should allow to have more than one party together, so that if some party is some issues and other party can then make the other issues that they are more knowledgeable about.
(Maybe the result is that there is no single prime minister, but maybe that isn't the result; I don't know.)
And then you end up with another copy of some party.